<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en">
<head>
	<meta http-equiv="Content-Type" content="text/html;charset=UTF-8">
	<title>选择器</title>
	<style type="text/css">
		#content{
			width: 400px;
			height: 400px;
			background-color: green;
			display: block;
		}
		.class1{
			font-size: 40px;
			border:1px solid red;
		}
		.class2{
			color: blue;
		}
		p{
			line-height: 30px;
			text-indent: 2em;/*记住*/
			white-space: nowrap;
		}
	</style>
</head>
<body>
	2、类选择器
	<div class="class1 class2" >seq3wrqwerqw3rqwerqwerqwerqwre</div>
	<hr />
	1、id选择器
	<div id="content"></div>
</body>
</html>